Hitler’s megalomaniacal impulses led him to demand the construction of the largest tank the world had ever seen – a mobile fortress weighing 180 tons. But even this colossus couldn’t satisfy Hitler’s thirst for enormous weapons of war, as he went on to request a land battleship weighing 1,000 tons. This is the story of the Nazi engineers tasked with fulfilling that dream, and an arms race that resulted in the evolution of super-guns and tanks.